Slide valve assembly for the fluid pressure power cylinders of duplex reciprocators



March 16, 1948. G. K. JoHNsToNE y 2,437,854

SLIDE VALVE ASSEMBLY Fon THE'FLUID PRESSURE PowER CYLINDERS oF DUPLEXRECIPRocAToRs Filed June 5, 1945 2 Sheets-Sheet l $4@ om gia-...L

March 16, 1948. G, K JOHNSTQNE 2,437,854

SLIDE VALVE ASSEMBLY FOR THE FLUID PRESSURE POWER CYLINDERS OF DUPLEXRECIPROCATORS Filed June 5, 1945 2 Sheets-Sheet 2 w I *E* EST 3 'A d lL'lu QSE x Patented Mar. 16, 1948 SLIDE VALVE ASSEIWB PRESSURE LY FOR THEFLUID POWER CYLINDERS F DU- PLEX RECIPROCATOR George KirkpatrickJohnstone, Glasgow, Scotland, assigner to J. H. Carruthers & CompanyLimited, Glasgow, Scotland, a corporation oi' Great Britain ApplicationJ une 5, 1945, Serial No. 597,705

In Great Britain November 17, 1943 2 Claims.

This invention relates to a slide valve assembly for the Yduid pressurepower cylinders of a duplex reciprocator, such as, for example, a duplexpump, and may be regarded as a further development of the constructiondescribed in the prior British Patent speciiication No. 177,115.

In the said prior specification there is described main valve beingpiston of the cylinder other serves, and each cut-oir valve beingoperated from the piston of the cylinder A slide valve assemblyaccording to the invention includes two mam slide valves and two cut-Referring to the drawings. the slide valve a-ssembly shown includes twomain valves G and H, and two cut-01T valves L and K operating on thebacks of the main valves.

Each main valve is operated from the piston of the cylinder other thanthat which it serves. and

the cylinder which it serves.

The main and cut-01T valves are constituted by simple slab-like portedmembers disposed between two valve-operating spindles A a valve chest Cpresenting a ported face D from which passages connect with the ends ofthe two cylinders A and B, respectively.

Secured on each of the spindles A' and B' are' two pairs of inwardlyprojecting lugs spaced apart axially on the respective spindle. One pairoi. lugs E engages the ends of one main valve, and the other pair oflugs F engages the ends of the cut-o" valve associated with the othermain valve. Thus, as in the prior construction, each valve spindle A orB', actuated from one of the piston rods A2 or B2 of the pump, eiiectsjoint reciprocation of one main valve and one cut-ofi valve.

'Ihe lugs are unitary with bracket bosses E" and F penetrated by andsecured on the respective spindles and aiording reciprocating guidesengaging plane guide faces M on the lateral walls ci the valve chest C.The bracket bosses E and F serve also to locate the valves laterally andthus to confine the valves in their proper positions on the ported faceD of the chest C.

The two lugs on each spindle which engage the inner ends of the valvesactuated by such spindle are formed unitary with a common long bracketboss E F secured on the respective spindle.

As will be understood, the construction proin the guided.

I claim: 1. A slide valve assembly for the iiuid pressure powercylinders of a duplex reciprocator, including a valve chest, two mainslide valves and two cut-ofi valves operating on the backs of said mainvalves within said valve chest, two valve-actuating reciprocatoryspindles, lugs attached to said spindles, the lugs on each spindleengaging one main slide valve and one cut-oi valve so as to impartreciprocating movements to said valves, and guide-forming memberscarried by sad'spindles and engaging guide surfaces within said valvechest.

2. A slide valve assembly for the iiuid pressure power cylinders of aduplex reciprocator, including a valve chest, two main slide valves, acut-olf other main slide valve.

GEORGE HRIQJATRICK JOHNSTONE.

REFERENCES CITED The following references are 4of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 455,555 Worthington July 7, 18911,453,029 Twells Apr. 24, 1923 FOREIGN PATENTS Number Country Date177,115 Great Britain Mar. 23, 1922

